Chemotherapy of human small-cell gastrointestinal carcinoma xenografts in nude mice.

We established two xenografts of small-cell carcinoma (SCC) arising in the oesophagus or the stomach, designated TEG13 and TSG15, and investigated the responses to experimental chemotherapy on these strains. Both tumours were classified as the intermediate cell type of SCC composed of small cells having neuroendocrine features in terms of morphology, argyrophil property, and immunoreactivity for neuron-specific enolase. Mitomycin C, cisplatin, and cyclophosphamide were judged to be effective against both strains. Particularly, cisplatin produced almost complete regression of tumour growth of the TEG13 strain. Etoposide proved effective only against the TSG15 strain. Moreover, the combined treatment with etoposide and cisplatin produced the most pronounced antitumour effect against the TSG15 strain. These studies suggest that cisplatin may be a key drug for chemotherapy of oesophageal SCC, and etoposide plus cisplatin treatment may be especially recommended in the treatment of gastric SCC. Mitomycin C should be re-evaluated in gastrointestinal SCC.